consumer wrote:
I read through this post, but never saw anyone respond to this idea: Is there any merit to multiplying the gain in order to exaggerate the offset?

Or would that just introduce more uncertainty?

I'd say no merit since at least the garden variety opamps that aren't specifically marketed as low offset probably have input offset specs in the mV range themselves.

I have to admit all this talk about the DMM digits in this thread has me confused anyway. Isn't the whole point of these "differential" circuits that you don't have to measure absolute voltage but only relative one? How many digits the DMM has is pretty irrelevant as long as it has a mV range setting.

true, matching is a relative measurement. That's why such a simple thing like YATMA can match to 50uV if you need it without precision DVM.viewtopic.php?t=153845

elektrouwe wrote:
true, matching is a relative measurement. That's why such a simple thing like YATMA can match to 50uV if you need it without precision DVM.viewtopic.php?t=153845

I may have said this further up the thread, but: I love my YATMA! It is a very useful device and makes transistor matching actually enjoyable Thank you elektrouwe.

As a practical point, I have found the YATMA much easier and faster to use than my build of the Fritz circuit. Obviously it took a few more hours to put together but the time saved since and the reliable matches found are worth it, to me at least.

Hi, I bought an Ian Fritz transistor matching kit. I assembled the pcb but I'm wondering how I power it. It comes with a small ribbon cable, but what should I connect the ribbon cable to? Can I rig it to power of a 9V battery?